Wire and cable press machine

1、 Product Overview

Wire and cable press machineIt is in the same category of productsYDJ（G）On the basis of the high-voltage test transformer, according to the national standard for test transformersDL/T848.2—2004Requirement: A new type of product produced after improvement, this series of products has the characteristics of small size, light weight, compact structure, complete functions, and easy use. Practical for power, industrial and mining, scientific research and other departments, it is an instrument required for conducting power frequency withstand voltage tests and DC leakage tests on various high-voltage electrical equipment, electrical components, and insulation materials in high-voltage testing.

Meaning of type code: No type code indicates communication product(JZ) -AC/DC dual-use products

(JC) -Communicating serial products(JZC) -AC/DC series excited products.

IIWire and cable press machineproduct structure

The iron core of the series high-voltage test transformer is a single frame type. The coil adopts a multi-layer tower structure with the same core cylinder. The primary low-voltage winding is wound on the iron core, and the secondary high-voltage winding is wound on the outside of the low-voltage winding. This coaxial arrangement reduces the coupling loss between the windings. The high-voltage silicon stack is encapsulated in a sleeve using a special process, and the outer shell of the product is made into an octagonal structure that fits well with the core, resulting in an overall beautiful and elegant appearance. The internal and external structures are shown in the diagram1.

1-Equal pressure ball;2-Silicon stack short-circuit rod;3-High voltage casing;4-Oil valve;5-Shell;6、7-Adjust voltage inputaThexTerminal;

8、9-apparatus measuringETheFTerminal;10-High pressure tailXTerminal;11-Grounding terminal of transformer casing;12-high voltage outputATerminal;13-High voltage rectifier silicon stack;14-Internal pressure equalization ring;15-Transformer iron core;16-Primary low-voltage winding;17-Measuring instrument winding;18-Secondary high voltage winding;19-Transformer oil.

3、 Working principle

1The series of cable compression equipment is a single-phase transformer with a connection group labelIIThe working process of a single high-voltage test transformer is conducted using alternating current220V（10KVAThe above is380V）The voltage is connected to the power control box (platform) and is regulated by the self coupling voltage regulator inside the power control box (platform)（50KVAThe above regulator is attached for external adjustment0~200V（10KVAabove0~400V）The voltage is applied to the primary winding of the test transformer, and according to the principle of electromagnetic induction, the high voltage required for the test can be obtained in the high-voltage winding of the test transformer. The working principle diagram is shown in the figure2As shown.

In the experimental transformer:aThexFor low voltage input terminal;ATheXFor the high-voltage output terminal;ETheFFor the instrument measurement end.

2The working principle of a single AC/DC dual-purpose high-voltage test transformer is shown in the figure3As shown in the figure, the high-voltage bushing is equipped with a rectifier silicon stack, which is connected in series in the high-voltage circuit for high-voltage rectification to obtain high DC voltage. When a short-circuit rod is used to short-circuit the high-voltage silicon stack, AC high voltage can be obtained, and its state is AC output; On the contrary, when the short-circuit rod is pulled out, its state is DC output.

In the experimental transformer:aThexFor low voltage input terminal;ATheXFor the high-voltage output terminal;ETheFFor the instrument measurement end.

1-High voltage rectifier silicon stack;2-Silicon stack short-circuit rod.

3The principle of obtaining higher voltage through series excitation of three high-voltage test transformers is shown in the figure4The series excited high-voltage test transformer has great flexibility because the entire test device consists of multiple single series excited test transformers. Each single test transformer has the characteristics of small size, light weight, and easy transportation. It can be connected in series to form a single test transformer with output voltage several times higher, or used separately. The entire experimental setup requires minimal investment and is cost-effective. image3As shown: In the series excitation use of three series excitation test transformers, a single test transformerB1TheB2TheB3The output voltage isUThe first and second stage test transformers both have an excitation winding inside, which isA1TheC1andA2TheC2When the control voltage is applied to the first stage test transformerB1The primary windinga1Thex1Up, excitation windingA1TheC1Provide a test transformerB2Primary winding power supply, secondary test transformerB2The excitation windingA2TheC2Provide the test transformerB3The primary winding is powered. Due to the first level test transformerB1High voltage tail and shell grounding, second and third stage test transformersB2andB3Isolation with insulated brackets on the ground, thisSample test transformerB1TheB2TheB3The output voltages to ground are1UThe2UThe3U.

B1TheB2TheB3-Series excited high-voltage transformer;1UThe2UThe3U-Ground voltage at all levels;

PV-High voltage indication table（KV）；ZJ1TheZJ2-Insulated bracket.

4、 Usage and precautions

1The wiring method for conducting power frequency withstand voltage test on high-voltage test transformers is shown in the figure5Before conducting the power frequency withstand voltage test, select the current limiting resistor based on the rated capacity of the test transformer,(water resistance)The resistance value of the discharge ball gap should be adjusted according to the required high voltage value of the test sample. In order to improve the measurement accuracy of the applied voltage to the test sample, it should be connected to the high voltage sideFRCResistive capacitive voltage divider is used to measure voltage.

According to the diagram5Combined with the diagram2The power frequency withstand voltage test conducted involves connecting the working circuit and testing the high voltage winding of the transformerXEnd (high pressure tail), instrument measurement windingFThe casing of the terminal and test transformer, as well as the casing of the power control box (platform), must be reliably grounded.

When conducting a power frequency withstand voltage test using three test transformers in series, the primary winding of the second and third stage test transformersXEnd, instrument measurement windingFEnd and high voltage windingXBoth ends (high pressure tail) are connected to the outer shell of the current stage test transformer, and the main bodies of the second and third stage test transformers must be placed on insulated supports. Except for the first level, the main body of the second and third level test transformers should not be grounded. The wiring method is shown in the figure4As shown.

Before connecting to the power supply, the voltage regulator of the power control box (platform) must be set to zero position. After connecting the power supply, the green indicator light will turn on. Press the start button once, and the red indicator light will turn on, indicating that the test transformer has been connected to the control power supply and started to increase the voltage.

R1TheR2-Current limiting resistor;Qx-Discharge ball gap;Zx-Subject matter;

FRC-Resistive capacitive voltage divider;V-High pressure gauge for voltage divider.

Start from zero position and rotate the regulator handwheel clockwise at a constant speed to increase the pressure. (Boosting methods include: fast boosting method, i.e20SStep by step boosting method, slow boosting method, i.e60SStep by step boosting method, extremely slow boosting method available) The voltage is raised from zero to the rated test voltage you require at the selected boosting speed75%Afterwards, at a rate of per second2%Raise the speed of the rated test voltage to the desired test voltage, and pay close attention to the indication of the measuring instrument and the condition of the test object. After the time for applying voltage to the test object is up. The regulator should be returned at a constant speed within a few seconds, and the high pressure should be reduced to1/3Below the test voltage, press the stop button once to stop the high and low voltage output, and then cut off the power cord. The test is complete.

Precautions for the operation process of power frequency withstand voltage test

aTest personnel should divide their responsibilities properly,Set a safe distance for the test site,Carefully check the grounding condition of the test sample and the test transformer,And there is a dedicated person to monitor safety and observe the status of the test sample.

bThe main parts of the test sample should be cleaned thoroughly and kept absolutely dry to avoid damaging the test sample and causing errors in the test values.

cFor the testing of large equipment, it is generally necessary to first conduct a no-load test of the test transformer, that is, to increase the voltage to the test voltage without connecting the test sample, in order to calibrate the accuracy of the instrument's indication and adjust the ball spacing of the discharge ball gap.

dWhen conducting a voltage withstand test, the boosting speed should not be too fast, and sudden boosting should be prevented. For example, if the regulator is not at zero position, it should be suddenly closed, and the power should not be suddenly cut off. Generally, it should be closed when the regulator drops to zero position.

eDuring the boost or withstand voltage test, if any of the following abnormal situations are found,(1)The pointer of the voltage and current meter swings greatly,(2)The test sample made abnormal noises,(3)If insulation is found to be burnt or smoking, the voltage should be immediately reduced, the power should be cut off, the test should be stopped, and the cause should be identified.

fWhen using this product for high-voltage testing, in addition to being familiar with this manual, it is also necessary to strictly follow relevant national standards and operating procedures. Refer toGB311—83Preventive Testing Regulations for Electrical Equipment, etc.

2The wiring method for conducting DC withstand voltage and leakage tests on AC/DC dual-purpose high-voltage test transformers is shown in the figure6As it is a dual-purpose high-voltage test transformer for both AC and DC, the short-circuit rod of the high-voltage silicon stack should be extracted from the bushing to put the test transformer in a DC output state. Before conducting a DC leakage test, it is advisable to select the resistance value of the current limiting resistor (water resistor) based on the maximum rectification current of the high-voltage silicon stack at the output end during the leakage test, and then choose the capacitance value of the high-voltage filtering capacitor according to the requirements of the tested object for the DC high-voltage waveform. In order to improve the measurement accuracy of applying voltage to the test sample, it should be connected to the high voltage sideFRCResistive capacitive voltage divider is used to measure voltage.

image6Schematic diagram of wiring principle for DC leakage test

G-Silicon stack short-circuit rod;uA-Microampere meter;D-High voltage rectifier silicon stack.

According to the diagram6Combined with the diagram3Connect the working circuit of the DC leakage test conducted. The high-voltage winding of the test transformerXEnd (high pressure tail), instrument measurement windingFThe casing of the terminal and test transformer, as well as the casing of the power control box (platform), must be reliably grounded.

Before connecting to the power supply, the voltage regulator of the power control box (platform) must be set to zero position. After connecting the power supply, the green indicator light will turn on. Press the start button once, and the red indicator light will turn on, indicating that the test transformer has been connected to the control power supply and started to increase the voltage.

Start from zero position and rotate the regulator handwheel clockwise at a constant speed to increase the pressure. (Boosting methods include: fast boosting method)20SStep by step boosting method; Slow boost method, i.e60SStep by step boosting method; The voltage is increased from zero to the reference voltage at the rated test voltage or rated DC current at the selected boosting speed. During the experiment, close attention should be paid to the indication of the DC high voltage meter, leakage current meter, and the condition of the test object. After the experiment is completed, the high voltage should be uniformly lowered to zero, and the stop button should be pressed once to stop the high and low voltage output, and then the power should be cut off. At this point, a DC high-voltage discharge rod should be used to fully discharge the test sample and the testing device itself.

If conducting a cable DC test, as shown in the diagram6：CThe filtering capacitor does not need to be connected. (Because the cable itself is a capacitive test sample)

Precautions for DC leakage test operation process

（1）Test personnel should divide responsibilities, set a safe distance at the test site, carefully inspect the grounding of the test sample and test transformer, and assign a dedicated person to monitor safety and observe the status of the test sample.

（2）Before conducting the experiment on the test sample, all external connections should be removed and fully discharged. The main parts should be cleaned and kept absolutely dry to avoid damaging the test sample and causing errors in the test values.

（3）For large capacity test samples (capacitors, ultra long cables, etc.), the voltage should be slowly increased to prevent the microampere meter from being burned out due to excessive charging current of the test sample. If necessary, the microampere meter should be read for stable readings at different voltages by gradually increasing the voltage.

（4）During the experiment, the test object, microampere meter, and testing device should be closely monitored. In case of flickering, breakdown, or other phenomena, the voltage should be immediately reduced, the power should be cut off, and the cause should be identified.

5、 Supporting products

The following products are for selection only and require additional pricing at the time of purchase.

1.GHKZXSeries power control box capacity:1KVA~5KVAInput voltage:220V

2.GHKZTSeries power console capacity:10KVA~300KVAInput voltage:220Vor380V

3.Digital microampere meter:SWB

4.High voltage filtering capacitor:0.01uFThe40 ~ 100KV

5.High voltage DC discharge rod:GHFDB—70KV

6.Discharge ball gap:GHQXF—50、100、150、200、250、500

7.Standard oil tester:400ml

8.Folding handcart:150、300

9.Insulation bracket:（50、100、200、250、500）KV

10.Resistive capacitive voltage divider:FRC—（50、100、150、200）KV

11.High voltage silicon stack:（150、300、450,)KV

12.Water resistance:50The100